Manganese superoxide dismutase expression in endothelial progenitor cells accelerates wound healing in diabetic mice
Eric J. Marrotte, … , Jeffrey S. Hakim, Alex F. Chen
Eric J. Marrotte, … , Jeffrey S. Hakim, Alex F. Chen
Published November 8, 2010
Citation Information: J Clin Invest. 2010;120(12):4207-4219. https://doi.org/10.1172/JCI36858.
View: Text | PDF
Research Article Dermatology

Manganese superoxide dismutase expression in endothelial progenitor cells accelerates wound healing in diabetic mice

Abstract

Amputation as a result of impaired wound healing is a serious complication of diabetes. Inadequate angiogenesis contributes to poor wound healing in diabetic patients. Endothelial progenitor cells (EPCs) normally augment angiogenesis and wound repair but are functionally impaired in diabetics. Here we report that decreased expression of manganese superoxide dismutase (MnSOD) in EPCs contributes to impaired would healing in a mouse model of type 2 diabetes. A decreased frequency of circulating EPCs was detected in type 2 diabetic (db/db) mice, and when isolated, these cells exhibited decreased expression and activity of MnSOD. Wound healing and angiogenesis were markedly delayed in diabetic mice compared with normal controls. For cell therapy, topical transplantation of EPCs onto excisional wounds in diabetic mice demonstrated that diabetic EPCs were less effective than normal EPCs at accelerating wound closure. Transplantation of diabetic EPCs after MnSOD gene therapy restored their ability to mediate angiogenesis and wound repair. Conversely, siRNA-mediated knockdown of MnSOD in normal EPCs reduced their activity in diabetic wound healing assays. Increasing the number of transplanted diabetic EPCs also improved the rate of wound closure. Our findings demonstrate that cell therapy using diabetic EPCs after ex vivo MnSOD gene transfer accelerates their ability to heal wounds in a mouse model of type 2 diabetes.

Authors

Eric J. Marrotte, Dan-Dan Chen, Jeffrey S. Hakim, Alex F. Chen

×

Figure 9

In vivo integration of transplanted EPCs on day 6 of wound healing.

Options: View larger image (or click on image) Download as PowerPoint
Wound angiogenesis after 6-mm punch biopsy. (A) There were significantly...
At the time of wounding, 2 × 106 BrdU-labeled db/+ EPCs were transplanted onto 6-mm punch biopsy wounds of db/db mice. On day 6 of wound healing, wounds were isolated, fixed, and stained for BrdU (brown stained cells). (A–D) Typical photographs demonstrate EPC integration into the dermis and vascular structure. Boxed regions are shown at higher magnification to the right. The green arrow points to BrdU-positive capillaries. Scale bar: 500 μm (A); 100 μm (B and C); 50 μm (D). (E–H) To ascertain that BrdU-labeled EPCs were incorporated into the capillary wall, wound tissues were stained for CD31, followed by BrdU staining. Typical photographs indicate that some BrdU-positive cells (red fluorescence) (E) were incorporated into CD31-positive vessels (green fluorescence) (F). White arrows point to CD31-positive cells. Remaining BrdU-positive cells surrounded the vessels. (G) The nucleus was counterstained with DAPI (blue fluorescence). The merged image is shown in H. The white boxed region indicates CD31/BrdU double-positive cells. Scale bar: 100 μm. Original magnification, ×40 (A); ×200 (E–H); ×200 (B and C); ×400 (D).